1. Field of the Invention
The invention relates generally to interconnectable, insulated flexible ventilation ducts. More specifically, the invention relates to preconditioned air ducts.
2. Related Art
During the time an aircraft is located adjacent to an airport gate, preconditioned air can be transported to the aircraft from a ground-based heating or air conditioning system. This is done through the use of insulated flexible duct which connects the heating or air conditioning unit of the airport with the internal ventilation system of the aircraft.
These ducts have been manufactured with various materials and in varying lengths to accommodate different types of aircraft. They are typically formed of several segments connected together through releasable connections. Depending upon the type of the aircraft being serviced, it is necessary to add or delete segments of the duct to establish a suitable and appropriate connection of the aircraft ventilation system with the ground-based unit. The releasable connections can comprise zippers or hook and loop fasteners, such as VELCRO.RTM.. An example of a duct assembly employing hook and loop fasteners to interconnect adjacent segments of the ducts shown in U.S. Pat. No. 5,368,341 (Larson), issued Nov. 29, 1994.
The need exists for more durable ventilation duct, given the harsh rigors of its typical use on airport ramps, along with a need for a greater degree of protection for the insulation and for the connections.